diff options
Diffstat (limited to 'lib/libprocstat/core.c')
| -rw-r--r-- | lib/libprocstat/core.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/lib/libprocstat/core.c b/lib/libprocstat/core.c new file mode 100644 index 0000000..1ada459 --- /dev/null +++ b/lib/libprocstat/core.c @@ -0,0 +1,262 @@ +/*- + * Copyright (c) 2013 Mikolaj Golub <trociny@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/elf.h> +#include <sys/user.h> + +#include <assert.h> +#include <err.h> +#include <fcntl.h> +#include <gelf.h> +#include <libelf.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "core.h" + +#define PROCSTAT_CORE_MAGIC 0x012DADB8 +struct procstat_core +{ + int pc_magic; + int pc_fd; + Elf *pc_elf; + GElf_Ehdr pc_ehdr; + GElf_Phdr pc_phdr; +}; + +static bool core_offset(struct procstat_core *core, off_t offset); +static bool core_read(struct procstat_core *core, void *buf, size_t len); + +struct procstat_core * +procstat_core_open(const char *filename) +{ + struct procstat_core *core; + Elf *e; + GElf_Ehdr ehdr; + GElf_Phdr phdr; + size_t nph; + int fd, i; + + if (elf_version(EV_CURRENT) == EV_NONE) { + warnx("ELF library too old"); + return (NULL); + } + fd = open(filename, O_RDONLY, 0); + if (fd == -1) { + warn("open(%s)", filename); + return (NULL); + } + e = elf_begin(fd, ELF_C_READ, NULL); + if (e == NULL) { + warnx("elf_begin: %s", elf_errmsg(-1)); + goto fail; + } + if (elf_kind(e) != ELF_K_ELF) { + warnx("%s is not an ELF object", filename); + goto fail; + } + if (gelf_getehdr(e, &ehdr) == NULL) { + warnx("gelf_getehdr: %s", elf_errmsg(-1)); + goto fail; + } + if (ehdr.e_type != ET_CORE) { + warnx("%s is not a CORE file", filename); + goto fail; + } + if (elf_getphnum(e, &nph) == 0) { + warnx("program headers not found"); + goto fail; + } + for (i = 0; i < ehdr.e_phnum; i++) { + if (gelf_getphdr(e, i, &phdr) != &phdr) { + warnx("gelf_getphdr: %s", elf_errmsg(-1)); + goto fail; + } + if (phdr.p_type == PT_NOTE) + break; + } + if (i == ehdr.e_phnum) { + warnx("NOTE program header not found"); + goto fail; + } + core = malloc(sizeof(struct procstat_core)); + if (core == NULL) { + warn("malloc(%zu)", sizeof(struct procstat_core)); + goto fail; + } + core->pc_magic = PROCSTAT_CORE_MAGIC; + core->pc_fd = fd; + core->pc_elf = e; + core->pc_ehdr = ehdr; + core->pc_phdr = phdr; + + return (core); +fail: + if (e != NULL) + elf_end(e); + close(fd); + + return (NULL); +} + +void +procstat_core_close(struct procstat_core *core) +{ + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + elf_end(core->pc_elf); + close(core->pc_fd); + free(core); +} + +void * +procstat_core_get(struct procstat_core *core, enum psc_type type, void *buf, + size_t *lenp) +{ + Elf_Note nhdr; + off_t offset, eoffset; + void *freebuf; + size_t len; + u_int32_t n_type; + int cstructsize, structsize; + char nbuf[8]; + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + switch(type) { + case PSC_TYPE_PROC: + n_type = NT_PROCSTAT_PROC; + structsize = sizeof(struct kinfo_proc); + break; + case PSC_TYPE_FILES: + n_type = NT_PROCSTAT_FILES; + structsize = sizeof(struct kinfo_file); + break; + case PSC_TYPE_VMMAP: + n_type = NT_PROCSTAT_VMMAP; + structsize = sizeof(struct kinfo_vmentry); + break; + default: + warnx("unknown core stat type: %d", type); + return (NULL); + } + + offset = core->pc_phdr.p_offset; + eoffset = offset + core->pc_phdr.p_filesz; + + while (offset < eoffset) { + if (!core_offset(core, offset)) + return (NULL); + if (!core_read(core, &nhdr, sizeof(nhdr))) + return (NULL); + + offset += sizeof(nhdr) + + roundup2(nhdr.n_namesz, sizeof(Elf32_Size)) + + roundup2(nhdr.n_descsz, sizeof(Elf32_Size)); + + if (nhdr.n_namesz == 0 && nhdr.n_descsz == 0) + break; + if (nhdr.n_type != n_type) + continue; + if (nhdr.n_namesz != 8) + continue; + if (!core_read(core, nbuf, sizeof(nbuf))) + return (NULL); + if (strcmp(nbuf, "FreeBSD") != 0) + continue; + if (nhdr.n_descsz < sizeof(cstructsize)) { + warnx("corrupted core file"); + return (NULL); + } + if (!core_read(core, &cstructsize, sizeof(cstructsize))) + return (NULL); + if (cstructsize != structsize) { + warnx("version mismatch"); + return (NULL); + } + len = nhdr.n_descsz - sizeof(cstructsize); + if (len == 0) + return (NULL); + if (buf != NULL) { + len = MIN(len, *lenp); + freebuf = NULL; + } else { + freebuf = buf = malloc(len); + if (buf == NULL) { + warn("malloc(%zu)", len); + return (NULL); + } + } + if (!core_read(core, buf, len)) { + free(freebuf); + return (NULL); + } + *lenp = len; + return (buf); + } + + return (NULL); +} + +static bool +core_offset(struct procstat_core *core, off_t offset) +{ + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + if (lseek(core->pc_fd, offset, SEEK_SET) == -1) { + warn("core: lseek(%jd)", (intmax_t)offset); + return (false); + } + return (true); +} + +static bool +core_read(struct procstat_core *core, void *buf, size_t len) +{ + ssize_t n; + + assert(core->pc_magic == PROCSTAT_CORE_MAGIC); + + n = read(core->pc_fd, buf, len); + if (n == -1) { + warn("core: read"); + return (false); + } + if (n < (ssize_t)len) { + warnx("core: short read"); + return (false); + } + return (true); +} |
